Originally Posted by onyxjl
I see the femur rotating in the hip socket as an explanation of a result to be useful, but I personally don't find the idea of rotating my femur as an instruction to be particularly useful as I find it a rather difficult movement to isolate.
When I tip my foot, my knee and I assume (as I can't really see it only feel it in my hip and knee) my femur move. Accounting for situations like disski's, if tipping the foot causes the ski to edge and move the knee and femur into the appropriate places why would one want to focus on rotating the femur instead? Tipping the foot is a very easy movement to isolate.
It's not that rotating the femur is difficult to grasp, rather why place the action so far away from the ski to obtain that result when tipping the foot does the same job? That's what my dislike for the instruction to rotate one's femur stems from not the explanation that it does.
Am I misunderstood that the reason one would focus on either tipping the foot or rotating the femur is that it places the ski on edge and the body in a strong position to support that edge? Does rotating the femur have some effect that tipping the foot doesn't provide?
Well put. Yes, the rotary movement of the femur does indeed increase the flexion of the outside knee, thus increasing the load on the front of the outside ski, or, allows one to steer that foot independently of the inside ski/foot.
The rotary motion of the femur on the inside leg likewise increases the inward flex of that knee and aligns the skier properly to bias the inside ski enhancing the carve of that ski.
If you stand in an athletic position you can tip both feet without getting the anatomical affect of the aforementioned as tipping of the foot is either pronating or supinating the ankle, purely a lateral movement. Makes sense?
Here's how you can isolate the rotary motion of the femur turning in the hip socket. Hold either leg out to the side approximately 6" off the ground. Keep the leg straight and treat the foot as if in a ski boot. Turn the femur and the foot will rotate in or out. You probably will have about 45 - 60 Degrees range of motion.
Next put your foot down and make the same motion toward the inside of your body. Notice how much pressure you can develop along the inside arch/edge of your foot. When a ski is attached to the foot, the rotary movement of the femur creates powerful forces to the ski - either ski and this can be used with sequential or simultaneous movement of the legs.
Hope this helps make sense of that verbal cue. I have found it works spectacularly with my racing students as long as I, as dchan suggests, make sure my students understand the instruction through my explanations and demonstrations.